With so many outstanding properties : High Strength- Super Low Impermeability -Great Chemical resistance , geomembrane is widely used on environmental and anti-seepage engineering .such as environmental protection , water conservancy projects , municipal engineering , landscaping engineering ,petrochemical industry . But maybe you don’t know there are 3 types of them: HDPE liner , LLDPE liners , PVC liners. HDPE geomembrane is the most popular type. HDPE, PVC and LLDPE geomembranes are all commonly used as liners in anti-seepage engineering projects , However, they differ significantly in terms of raw material properties, performance parameters, and applicable scenarios.
Differences between Raw Materials and Production Process
HDPE geomembrane Raw Material: High-density polyethylene resin is the primary raw material, with a regular molecular structure and high crystallinity (80%-90%). Production Process: Made through blow molding or calendering, the thickness is typically 0.2mm-3mm. Antioxidants, UV stabilizers, and other additives may be added to improve durability. PVC geomembrane Raw Material: Based on polyvinyl chloride resin, plasticizers (such as phthalates), stabilizers, and fillers are added. The plasticizer content directly affects flexibility. Production Process: Calendering is the primary method. The thickness is typically 0.5mm-2mm. Reinforced or unreinforced geomembranes are available (reinforcement improves tear resistance). LLDPE geomembrane Raw material: Linear low-density polyethylene (LLDPE), produced through the copolymerization of ethylene and α-olefins. Its molecular chain exhibits a linear structure and a low crystallinity (20%-30%). Production process: Blow molding is often used. Thickness typically ranges from 0.3mm to 2mm. It exhibits excellent flexibility and can be treated with anti-aging agents to enhance its suitability for outdoor environments.
Feathers Comparison of HDPE PVC LLDPE Geomembrane
Differences in Application Scenarios
HDPE Geomembrane Advantages: Large-scale anti-seepage projects requiring high strength and durability, such as landfills (seepage prevention and filtrate leakage prevention); water conservancy projects (reservoirs, dams, and canals); chemical wastewater ponds (biogas digester)and tailings ponds (resistance to highly corrosive environments).
Limitations: Moderate flexibility makes it unsuitable for areas with complex terrain and prone to deformation.
PVC Geomembrane Advantages: Applications requiring high flexibility but lower heat and chemical resistance, such as landscape lakes and constructed wetlands (easy construction and adaptability to minor settlements); temporary anti-seepage projects (low cost and stable short-term use). Limitations: Plasticizer migration can easily lead to aging and brittleness, making it unsuitable for high-temperature and strong solvent environments, and its environmental profile is controversial (it contains chlorine).
LLDPE geomembrane: Due to it’s very close density compared to HDPE liner , their characteristics are similar . HDPE liner with 0.94g/cc VS LLDPE liner with 0.939g/cc
Summary of HDPE LLDEP PVC Geomembrane
Life-span : HDPE (over 50 years) > LLDPE (30-50 years) > PVC (10-20 years, affected by plasticizer migration)
Tensile Strength: HDPE > LLDPE > PVC
Flexibility : HDPE ≈ LLDPE < PVC
Anti UV and Anti-Oxidation: HDPE > LLDPE > PVC
Compliance : HDPE ≈ LLDPE < PVC
Environmental Performance: HDPE and LLDPE are more recyclable, while PVC, due to its chlorine and plasticizer content, is difficult to recycle and less environmentally friendly .
The selection process should be based on a comprehensive assessment of the project's anti-seepage requirements, environmental conditions (temperature, media), terrain complexity, and service life:
Select HDPE for high strength, corrosion resistance, and long-term use;
Select PVC for low cost ,short-term flexibility and complex terrain;
As HDPE geomembrane are with similar characteristics with LLDPE liner , most clients choose HDPE liner for their projects directly.